Method and apparatus for introducing foreign substances into vacuum tube lights



Oct. 6, '1931. c, M E 1,826,383

METHOD AND APPARATUS FOR INTRODUCING FOREIGN SUBSTANCES INTO VACUUM TUBE LIGHTS Filed May '1, 1925 5 wucwtoz ROBERT C SMALL-EV .qgqmsva f Patented Oct. 6, 1931 UNITED} STATES PATENT...

oer-"Ice ROBERT c. smiLEY, E ARLINGTON, NEW JERSEY, ASSIGNOR To CLAUDE NEoN mom's, ma, on NEW YORK, N. Y., a oonroRATIo o NEw YORK METHOD AND Arrana'rus FOR INTRODUCING FOREIGN SUBSTANCES rNro vacuum- TUBE LIGHTS I "Application filed May 1, 1926. Serial No. 105,894.

This invention relates to a method and apparatus for introducing a forelgn substance into vacuum tube lamps. More speclfically it relates to a method and apparatus for introducing a substance, such as mercury, finely divided solids, etc., into the envelope of a vacuum tube lamp, such as one containing neon under reduced pressure.

In the past it has been the practice to introduce mercury into lamps of the class described in order to modify the light emitted by the lam The mercury was introduced by distillatlon into the evacuated lamp envelope, either before or after the admission of the neon thereto. As will be readily understood, the apparatus required for the distillation of mercury is complicated and more or less difficult to operate and is to a certain degree dangerous to the operator. Moreover, only liquids and solids capable of distillation can be so introduced.

It is an object of thisinvention to produce a process and apparatus whereby foreign substances such as mercury and the like may be introduced in their normal state into the lamp envelope,

It is still a further ob'ectof my invention to produce a method and apparatus whereby substances incapable of being distilled, may be introduced bodily into a lamp. I

It is still a further object of my invention to provide a method and apparatus whereby foreign substances may 'be introduced into a lamp by the action of gravity and substantially without danger to the operator.

It is still a further object of my invention to provide a method and apparatus whereby foreign substances may be introduced into a lamp by relatively unskilled workers and by the use of simple apparatus. 7

It is still a further object of my invention to eliminate the disadvantages ofthe former method and to provide a new and improved method and apparatus for introducing for: eign substances into a lamp.

Still other objects will be apparent from the specification. V

Thefeatures of novelty which I believe to becharacteristics of my lnvention are point ed out with particularity in the appended of some foreign su claims. My invention itself however, will best be understood by reference to the specification aud accompanying drawings in which Figure 1 represents a container arranged to carry the foreign substance to ,be introduced into a lamp;

Figure 2 shows the container sealed to the 'lamp and having its interior communicating with the interior of-the lamp envelope; Figure 3 shows the container just after the envelope has beenevacuated and sealed as;

Figure 4 shows'the bodily transfer of a foreign substance from the container to the lamp envelope; and

Figure 5 the lam envelope after the container has been sealied oil andremoved. I

' Referring nowmore particularly to Figure 1, l designates a-section of tubing pref erably'of glass, hating a second portion 2 sealed thereon to form a T. The lowerend of the stem of the T is closed ofi as at 3 and the substance to be transferred to the interior of the lamp is placed therein as indicated at 4. If desircd a neck portion 5 may be formed on the T on each side of the stem thereof, or at one side only if desired for convenience in sealing ofi and removing portions of the tube.

Referring now to Figure 2 I have shown diagrammaticall a lamp envelope 6 consis'tlngof a portion of tubing terminating at either end in bulbs 7 containin for example,

interior electrodes 8 mounte upon lead-in and'to sup 1y with neon under reduced presi sure and a so to supply with a small amount tance, suchfor example as mercury, the T tube 1 will be sealed to the lamp envelope 6 as at 12 in such a manneras to'establish contact between the interior of the T tube and the interior of the lamp envelope. The. junction 12 between T tube velope.

1 and the lamp envelope 6 should be made airtight for a purpose which will be explained later. The opposite open end of the T tube 1 may and preferably will be connected to tube 13 leading off to suitable pumps or other evacuating apparatus not shown, so that the lamp may be evacuated through tube 1, thereby avoiding the necessity of making another connection to evacuate the lamp en- Either before or after the T tube 1 is sealed to the lamp envelope, the material which it is desired to transfer to the interior of the lamp envelope will be placed in the stem of the T as shown at 4. The pumps may now be started and the interior of the lamp envelope 6 evacuated. It is to be understood of course, that any necessary heating of the lamp envelope may take place at this time either with or without the passage of current through the lamp and either with or without supplemental heating of the electrodes to drive off occluded gases.

Since the material to be introduced is in the pocket 4, out of the path of current flow in the gas, the passage of current will not cause vaporization of the material to be introduced into the lamp, and its consequent withdrawal from the lamp by the pump, which must be avoided.

After the tube has been properly evacuated, the evacuating apparatus may be disconnected and the proper amount of desired gas, such for example as neon, introduced by opening a valve (not shown) in the evacuating lme. v

t is now evident that the tube has been evacuated and that it has been supplied with the proper amount of gas for'oper-ation. It should now be sealedofl which may be done, for example by bringing a flame from a burner 15 to pla upon the tube 1 betweenthe junc- %ion of the and the connection to the exhaust The tube may now be aged and tested to make sure that it has the proper operating characteristics, before the introduction of the forei n substance. After the tube has been teste and found in ood order the lamp envelope with the T tu attached thereto may be manipulated in a suitable manner to cause the foreign substance, such as mercury 4, to flow down the stem of the T and down the top thereof as shown in Figure 4 into the envelope 6 of the lamp" proper. The simplest way of producing this result is sim ly to invert and tilt the lamp after which t eT tube may be tapped gently to dislodge the foreign substance if it be. a solid. r

The substance has now been introduced and the lamp will now have the desired operat' ing characteristics. However, the T tube, or what remains of it protrudes from the envelope and might be accidentally fractured thereby ruining the lamp. Therefore I prefer to seal off and remo e what is left of the T tube as shown in Figure 5 by bringing the burner 15 to the junction point 12 of the T tube and the lamp and sealing oh and removing the T tube will be readily understood.

It will be apparent that many foreign substances may be introduced in the manner shown and described and that while my process and apparatus is of particular advantage in inserting mercury inlo vacuum tube lamps,

lamp having a foreign substance contained therein which comprises scaling in communication with the interior of said envelope one end of a tube having a pocket therein arranged to hold said substance, connecting the other end of said tube to a pump, exhausting the envelope, scaling said tube at a point between said pocket and the connection to the pump, and transferring said substance from said pocket to said envelope.

2. The method of producing a vacuum tube lamp having a foreign substance contained therein which comprises scaling in communication with the interior of said envelope one end of a tube having a pocket therein ar ranged to hold said substance, connecting the other end of said tube to a pump, exhausting the envelope, sealing said tube between said pocket and the connection to the pump, transferring said substance from said pocket to said envelope and sealing off said tube.

3. The method of making a luminescent tube containing a rare gas and a foreign substance, which comprises sealing in communication with a luminescent tube a container into which the foreign substance'is introduced, exhausting the luminescent tube, in-

troducing a rare gas into the luminescent tube, transferring the foreign substance from the container to the luminescent tube while in the non-gaseous condition, and separating the said container from the said luminescent tube.

4. The method of making a luminescent tube containing a rare gas and mercury,

which comprises sealing in communication with a luminescent tube. a container arranged to hold'the mercury, introducing mercury into the container, exhausting the luminescent tube, introducing a rare gas into the luminescenttubc, transferring the mercury while in the non-gaseous condition from the container to'the luminescent tube, and sepa- Y tube containing a rare gas and mercury,

luminescent tube,

rating the said container from the said luminescent tube.

5. The method of making a luminescent tube containing a rare gas and a foreign substance which comprises sealing a container in communication with the luminescent tube, exhausting the luminescent tube, introducing a rare gas into the luminescent tube, and trans- I ferrin the foreign substance while in the non-gaseous condition from the container to the luminescent tube. I

6. The method of making a luminescent tube containing a rare gas and mercury, which comprises connecting a conduit with the luminescent tube, exhausting the luminescent tube, introducing a rare gas into the and transferring the mercury while in the non-gaseous condition from the conduit to the luminescent tube.

7. The method of making a luminescent tube containing a rare gas and a foreign substance, which comprises connecting a conduit with the luminescent tube, introducing a rare gas into the luminescent tube, and transferring the foreign substance while in the nongaseous condition from the conduit to the said luminescent tube.

8. The method of making a luminescent which comprises sealing in communication with the interor of the tube a container to hold mercury at a point suificientl remote from the lamp that it is not undul heated thereby, exhausting the tube, and ischarging mercury in its normal liquid state from said container into said luminescent tube.

9. The method of making a luminescent tube containing a rare gas and mercury, 

